linux-kernel - Re: [PATCH v6 13/18] perf: add support for taken branch sampling to perf report

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 23 Feb 2012 21:48:38 +0100
From:	Stephane Eranian <eranian@...gle.com>
To:	Arnaldo Carvalho de Melo <acme@...hat.com>
Cc:	Ingo Molnar <mingo@...e.hu>,
	Roberto Agostino Vitillo <ravitillo@....gov>,
	linux-kernel@...r.kernel.org, peterz@...radead.org,
	robert.richter@....com, ming.m.lin@...el.com, andi@...stfloor.org,
	asharma@...com, vweaver1@...s.utk.edu, khandual@...ux.vnet.ibm.com,
	dsahern@...il.com
Subject: Re: [PATCH v6 13/18] perf: add support for taken branch sampling to
 perf report

On Thu, Feb 23, 2012 at 7:11 PM, Arnaldo Carvalho de Melo
<acme@...hat.com> wrote:
> Em Thu, Feb 23, 2012 at 05:53:53PM +0100, Stephane Eranian escreveu:
>> Ok, so I looked at that today. Adding the feature bit is trivial.
>> But what's not easy is to get to the feature bit in perf report
>> by the time we need it. Very quickly after parsing the options,
>> we setup a bunch of things such as browser mode, sorting
>> order based on the -b option. But to get to the feature bit, we
>> would need to wait until after the session is created in
>> __cmd_report() which is way later.
>>
>> So we either hoist perf_session__new() very early, i.e., as soon
>> as we have the filename or we write yet another parse_header()
>> function just to get to the feature bits. I would rather choose the
>> first option. But none is really pretty...
>>
>> Arnaldo, any better idea?
>
> Humm, lemme see...
>
>
> By the time we need it is when we do setup_sorting, right? Perhaps we
> can delay that till after we do perf_session__new and thus have read the
> headers...
>
Well, there is also the UI setup (use_stdio setup_browser and the likes).
Then, yes, it's sorting.

> /me looks at the code.
>
> - Arnaldo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/